The outcome could cost farm jobs in Ohio and affect prices, opponents contend.

In 2008, the Humane Society played a key role in a California vote that changed the way farmers there must care for and shelter farm animals. Ohio became its next target, largely because of the state's 30 million egg-laying hens.

Battle lines formed this February with the Humane Society pitted against the powerful Ohio Farm Bureau Federation, Ohio Cattlemen's Association, Ohio Pork Producers Council and Ohio Poultry Association.

The message from the Humane Society was clear: Change your animal-husbandry practices or have them changed for you at the ballot box.

Said Humane Society President Wayne Pacelle, ''When we met with those industry leaders, we suggested we come to a meeting of the minds with a plan to phase out confinement systems in the state. My suggestion to agricultural leaders in Ohio was not to squander money on a campaign that was likely to fail.''